This invention relates to a character pattern segmentation system applied for character recognition of adjacent or touching handwritten character patterns.
The character pattern segmentation system is used in character recognition systems as an optical character reader for dividing touching character patterns into patterns of individual characters to be discriminated by a pattern recognizer when an input character pattern is found to be glued to another.
In a character pattern segmentation method disclosed in a Japanese patent application laid open as a Provisional Publication No. 121988/'89, a touching point of characters is detected by analyzing nodes of line segments which are obtained by abstracting and approximating ordinary dot pattern data into stroke data with no thickness, where nodes mean branching points of the abstracted line segments. The node analysis is performed for a collection of line segments, from which a farthest line segment is taken away one by one, from right hand, until a character is recognized uniquely.
In a Japanese patent application laid open as a Provisional Publication No. 98283/'84, there is disclosed a method of character segmentation and recognition, wherein an input touching character pattern is analyzed and classified to one of touching character combinations referring to a prepared list of patterns of various touching character combinations.
The character pattern segmentation method by node analysis described may involve unnecessary noise element as a lack of a line segment of a character data, because a dot pattern with a thickness to be divided into parts of two patterns may be abstracted into only a stroke line and sorted into either pattern.
The method of character segmentation and recognition in the Provisional Publication No. 98283/'94 needs no such pattern dividing but an enormous memory and a laborious work for preparing a reference list covering all patterns of touching character combinations.